freeCodeCamp/curriculum/challenges/chinese/10-coding-interview-prep/project-euler/problem-5-smallest-multiple.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
5900f3711000cf542c50fe84	Problem 5: Smallest multiple	1	302160	problem-5-smallest-multiple

--description--

2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.

能被从 1 到 n 的所有数整除的最小正数是多少？

--hints--

smallestMult(5) 应该返回数字

assert(typeof smallestMult(5) === 'number');

smallestMult(5) 应该返回 60。

assert.strictEqual(smallestMult(5), 60);

smallestMult(7) 应该返回 420。

assert.strictEqual(smallestMult(7), 420);

smallestMult(10) 应返回 2520。

assert.strictEqual(smallestMult(10), 2520);

smallestMult(13) 应返回 360360。

assert.strictEqual(smallestMult(13), 360360);

smallestMult(20) 应该返回 232792560。

assert.strictEqual(smallestMult(20), 232792560);

--seed--

--seed-contents--

function smallestMult(n) {

  return true;
}

smallestMult(20);

--solutions--

function smallestMult(n){
  function gcd(a, b) {
    return b === 0 ? a : gcd(b, a%b); // Euclidean algorithm
  }

  function lcm(a, b) {
    return a * b / gcd(a, b);
  }
  var result = 1;
  for(var i = 2; i <= n; i++) {
    result = lcm(result, i);
  }
  return result;
}